Document
19-5553; Rev 1; 1/11
TION KIT EVALUA BLE A IL A V A
1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output
General Description
The MAX5977A/MAX5977B hot-swap controllers provide complete protection for systems with a 1V to 16V singlesupply voltage. During the initial insertion, the hot-swap controllers limit the inrush current from damaging the board or from shorting out the backplane. When the input voltage is above the undervoltage threshold and below the overvoltage threshold, a 5FA current source powered from the internal 5V charge pump drives the gate of an external n-channel MOSFET, providing a slow turn-on response. An internal current-sense amplifier in the IC monitors the current across an external shunt resistor, providing current sensing for wide input-sense voltage range. The devices provide two levels of overcurrent circuit-breaker protections: a fast-trip threshold for a fast turn-off and a lower slow-trip threshold for a delayed turn-off. Exceeding either of the overcurrent circuit-breaker thresholds forces the device into fault mode where the external n-channel MOSFET is disabled. The MAX5977 is available in two versions that provide a latched-off (MAX5977A) or autoretry (MAX5977B) output when the device is in fault mode. A calibration mode allows further calibration of the integrated transconductance amplifier for production testing of the final design. The devices are offered in a 20-pin, 4mm x 4mm, TQFN-EP package and are fully specified from -40NC to +85NC.
VariableSpeed/BiLevel is a trademark of Maxim Integrated Products, Inc.
Features
S 1% Accurate Current-Sense Amplifier Output S Hot-Swap Monitors Operation from 1V to 16V S Integrated Charge Pump Fully Enhances the External n-Channel FET (VGATE = VIN + 5V) S VariableSpeed/BiLevelK Fault Protection Provides Electronic Circuit-Breaker Function S Output Latched Off After Fault Condition (MAX5977A) S Autoretry After Fault Condition (MAX5977B) S Power-Good Indicator S Calibration Mode S Small, 20-Pin, 4mm x 4mm TQFN-EP Package
MAX5977A/MAX5977B
Applications
Servers Storage Systems Network Switches and Routers General Hot-Swap
Ordering Information
PART MAX5977AETP+ MAX5977BETP+ PIN-PACKAGE 20 TQFN-EP* 20 TQFN-EP* FAULT RESPONSE Latched Autoretry
Note: All devices are specified over the -40NC to +85NC operating temperature range. +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad.
Typical Operating Circuit
VIN 1V TO 16V RSCOMP RCAL SCOMP CALSENSE FCOMP IN SENSE GATE SOURCE CSOUT CURRENT-SENSE AMPLIFIER OUTPUT RCSOUT CALIBRATION MODE INPUT 2.7V TO 16V PWR FAULT AGND GND PG FAULT OUTPUT POWER-GOOD OUTPUT CAL RFCOMP RSENSE TO LOAD RGATE CGATE CL
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MAX5977A MAX5977B
+3.3V
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output MAX5977A/MAX5977B
ABSOLUTE MAXIMUM RATINGS
PWR, SENSE, IN, FCOMP, SCOMP, GATE, SOURCE, CALSENSE to GND. ...................-0.3V to +28V PG, CAL, BIAS, UV, OV, FAULT, CSOUT to GND. ..-0.3V to +6V REG to GND.............................................................-0.3V to +4V GATE to SOURCE....................................................-0.3V to +6V IN to FCOMP, IN to SCOMP, IN to SENSE, IN to CALSENSE...................................................-0.3V to +1V GND to AGND.......................................................-0.3V to +0.3V FAULT, PG Current............................................ -1mA to +50mA GATE, SOURCE, GND Current.........................................750mA Input/Output Current (all other pins)...................................20mA Continuous Power Dissipation (TA = +70NC) 20-Pin TQFN, Single-Layer Board (derate 16.9mW/NC above +70NC)..........................1355.9mW 20-Pin TQFN, Multilayer Board (derate 25.6mW/NC above +70NC)..........................2051.3mW Junction-to-Ambient Thermal Resistance (Note 1) BJA, Single-Layer Board............................................ +59NC/W BJA, Multilayer Board................................................. +39NC/W Junction-to-Case Thermal Resistance (Note 1) BJC, Single-Layer and Multilayer Board...................... +6NC/W Operating Temperature Range........................... -40NC to +85NC Junction Temperature......................................................+150NC Storage Temperature Range. ............................ -65NC to +150NC Lead Temperature (soldering, 10s).................................+300NC Soldering Temperature (reflow).......................................+260NC
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer .